When Susan Monarez was sworn in to lead the US Centers for Disease Control and Prevention (CDC), the country’s premier public-health agency, many researchers across the country breathed a sigh of relief.
Trained as a microbiologist and immunologist, Monarez had been a non-partisan government scientist for nearly 20 years. She was an unexpectedly uncontroversial choice by US President Donald Trump, who had previously put forward (but later withdrew the nomination for) Dave Weldon, a physician and vaccine sceptic who worked as a Republican member of Congress from 1995 to 2009.
But in August, less than a month after assuming the role of director, Monarez was out. “I was fired for holding the line on scientific integrity,” she testified at a tense congressional hearing in September. According to her account, she refused orders from US health secretary Robert F. Kennedy Jr to fire leading scientists at the agency and to pre-approve vaccine recommendations without first considering the relevant scientific data.
Kennedy disputes this account, testifying that Monarez had told him that she wasn’t trustworthy, so he ousted her.
Kennedy has made no secret of his contempt for the CDC, calling it perhaps “the most corrupt agency” in the US government. A long-time anti-vaccine advocate, he has attempted to fire about one-quarter of the agency workforce and has replaced all the members of a key panel of scientists that advises the federal government on vaccine policy, introducing several members who have publicly criticized vaccines.
Monarez is one of the highest-profile government scientists to raise concerns about policy changes by the Trump administration that threaten public health. These are part of a broader set of actions that have disrupted the US scientific enterprise. Over the course of the year, US officials have cancelled thousands of grants, fired hundreds of government researchers, blocked funding to universities and proposed unprecedented cuts to research. The administration has said its actions are meant to improve science and innovation and restore the country’s confidence in scientific and public-health bodies.
“Susan has long established herself as someone who puts evidence in service of the country above all,” says Jennifer Nuzzo, an epidemiologist and director of the Pandemic Center at Brown University in Providence, Rhode Island. “Susan did what any self-respecting scientist would do. No self-respecting scientist would agree to just rubber-stamp things without first scrutinizing the scientific evidence.”
The CDC’s top medical officer, Debra Houry, and three other senior CDC scientists resigned in protest of Monarez’s dismissal. The conflict spilled into public view when Monarez, Houry and Kennedy presented their versions of events to US senators at hearings in September on Capitol Hill in Washington DC. Houry testified that Kennedy and his team had not consulted CDC’s scientists on key decisions, including one in May to limit access to COVID-19 vaccines to children and pregnant people.
The US Department of Health and Human Services, which includes the CDC and which Kennedy leads, disputes Houry’s testimony.
Monarez, whose previous government work spanned biosecurity, artificial intelligence and data analysis, had big plans for the agency that were focused largely on streamlining data to offer public-health recommendations tailored to each locality and state, she tells Nature. “I always challenge the status quo because that’s what you do in science,” Monarez says. “You challenge it to try to do better, but you don’t compromise your moral and scientific integrity for expediency.”